Planetary transmissions with three gear sets and a stationary interconnecting member

ABSTRACT

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets having six torque-transmitting mechanisms and two fixed interconnections. Also, one interconnecting member is continuously connected with the transmission housing. The powertrain includes an engine and torque converter that is not continuously connected to any of the planetary gear members and an output member that is continuously connected with at least one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the fixed interconnections, the input shaft, and the output shaft, and are operated in combinations of three to establish at least seven forward speed ratios and at least one reverse speed ratio.

TECHNICAL FIELD

The present invention relates to a family of power transmissions havingthree planetary gear sets that are controlled by six torque-transmittingdevices to provide at least seven forward speed ratios and one reversespeed ratio.

BACKGROUND OF THE INVENTION

Passenger vehicles include a powertrain that is comprised of an engine,multi-speed transmission, and a differential or final drive. Themulti-speed transmission increases the overall operating range of thevehicle by permitting the engine to operate through its torque range anumber of times. The number of forward speed ratios that are availablein the transmission determines the number of times the engine torquerange is repeated. Early automatic transmissions had two speed ranges.This severely limited the overall speed range of the vehicle andtherefore required a relatively large engine that could produce a widespeed and torque range. This resulted in the engine operating at aspecific fuel consumption point during cruising, other than the mostefficient point. Therefore, manually-shifted (countershafttransmissions) were the most popular.

With the advent of three- and four-speed automatic transmissions, theautomatic shifting (planetary gear) transmission increased in popularitywith the motoring public. These transmissions improved the operatingperformance and fuel economy of the vehicle. The increased number ofspeed ratios reduces the step size between ratios and therefore improvesthe shift quality of the transmission by making the ratio interchangessubstantially imperceptible to the operator under normal vehicleacceleration.

It has been suggested that the number of forward speed ratios beincreased to six or more. Six-speed transmissions are disclosed in U.S.Pat. No. 4,070,927 issued to Polak on Jan. 31, 1978; U.S. Pat. No.6,071,208 issued to Koivunen on Jun. 6, 2000; U.S. Pat. No. 5,106,352issued to Lepelletier on Apr. 21, 1992; and U.S. Pat. No. 5,599,251issued to Beim and McCarrick on Feb. 4, 1997.

Six-speed transmissions offer several advantages over four- andfive-speed transmissions, including improved vehicle acceleration andimproved fuel economy. While many trucks employ power transmissions,such as Polak, having six or more forward speed ratios, passenger carsare still manufactured with three- and four-speed automatictransmissions and relatively few five or six-speed devices due to thesize and complexity of these transmissions. The Polak transmissionprovides six forward speed ratios with three planetary gear sets, twoclutches, and three brakes. The Koivunen and Beim patents utilize sixtorque-transmitting devices including four brakes and two clutches toestablish six forward speed ratios and a reverse ratio. The Lepelletierpatent employs three planetary gear sets, three clutches and two brakesto provide six forward speeds. One of the planetary gear sets ispositioned and operated to establish two fixed speed input members forthe remaining two planetary gear sets.

Seven-speed transmissions are disclosed in U.S. Pat. No. 4,709,594 toMaeda; U.S. Pat. No. 6,053,839 to Baldwin et. al.; and U.S. Pat. No.6,083,135 to Baldwin et. al. Seven- and eight-speed transmissionsprovide further improvements in acceleration and fuel economy oversix-speed transmissions. However, like the six-speed transmissionsdiscussed above, the development of seven- and eight-speed transmissionshas been precluded because of complexity, size and cost.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved familyof transmissions having three planetary gear sets controlled to provideat least seven forward speed ratios and one reverse speed ratio.

In one aspect of the present invention, the family of transmissions hasthree planetary gear sets, each of which includes a first, second andthird member, which members may comprise a sun gear, a ring gear, or aplanet carrier assembly member.

In referring to the first, second and third gear sets in thisdescription and in the claims, these sets may be counted “first” to“third” in any order in the drawings (i.e., left to right, right toleft, etc.).

In another aspect of the present invention, each of the planetary gearsets may be of the single pinion-type or of the double pinion-type.

In yet another aspect of the present invention, the first member of thefirst planetary gear set is continuously interconnected to the firstmember of the second planetary gear set and a stationary member(transmission housing) through a first interconnecting member.

In yet another aspect of the present invention, the second member of thesecond planetary gear set is continuously interconnected with the firstmember of the third planetary gear set through a second interconnectingmember.

In yet a further aspect of the invention, each family memberincorporates an input shaft which is not continuously connected with amember of the planetary gear sets and an output shaft which iscontinuously connected with a member of the planetary gear sets.

In still a further aspect of the invention, a first torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst, second or third planetary gear set with the input shaft.

In another aspect of the invention, a second torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst, second or third planetary gear set or the second interconnectingmember with the input shaft.

In a still further aspect of the invention, a third torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst, second or third planetary gear set with the input shaft oranother member of the first, second or third planetary gear set.

In a still further aspect of the invention, a fourth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst planetary gear set or the second interconnecting member with amember of the second or third planetary gear set.

In a still further aspect of the invention, a fifth torque-transmittingmechanism, such as a clutch, selectively interconnects a member ofsecond planetary gear set or the second interconnecting member with amember of the first or third planetary gear set.

In still another aspect of the invention, a sixth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst, second or third planetary gear set with another member of thefirst, second or third planetary gear set.

In still another aspect of the invention, the six torque-transmittingmechanisms are selectively engageable in combinations of three to yieldat least seven forward speed ratios and at least one reverse speedratio.

The above objects and other objects, features, and advantages of thepresent invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic representation of a powertrain including aplanetary transmission incorporating a family member of the presentinvention;

FIG. 1b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 1a;

FIG. 2a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 2b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 2a;

FIG. 3a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 3b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 3a;

FIG. 4a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 4b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 4a;

FIG. 5a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 5b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 5a;

FIG. 6a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 6b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 6a;

FIG. 7a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 7b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 7a;

FIG. 8a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 8b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 8a;

FIG. 9a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 9b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 9a;

FIG. 10a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 10b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 10a;

FIG. 11a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 11b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 11a;

FIG. 12a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 12b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 12a;

FIG. 13a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention; and

FIG. 13b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 13a.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, wherein like characters represent the same orcorresponding parts throughout the several views, there is shown in FIG.1a a powertrain 10 having a conventional engine and torque converter 12,a planetary transmission 14, and a conventional final drive mechanism16.

The planetary transmission 14 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 18, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 18 includesthree planetary gear sets 20, 30 and 40.

The planetary gear set 20 includes a sun gear member 22, a ring gearmember 24, and a planet carrier assembly 26. The planet carrier assembly26 includes a plurality of pinion gears 27 rotatably mounted on acarrier member 29 and disposed in meshing relationship with both the sungear member 22 and the ring gear member 24.

The planetary gear set 30 includes a sun gear member 32, a ring gearmember 34, and a planet carrier assembly member 36. The planet carrierassembly member 36 includes a plurality of pinion gears 37 rotatablymounted on a carrier member 39 and disposed in meshing relationship withboth the sun gear member 32 and the ring gear member 34.

The planetary gear set 40 includes a sun gear member 42, a ring gearmember 44, and a planet carrier assembly member 46. The planet carrierassembly member 46 includes a plurality of pinion gears 47 rotatablymounted on a carrier member 49 and disposed in meshing relationship withboth the sun gear member 42 and the ring gear member 44.

The planetary gear arrangement also includes six torque-transmittingmechanisms 50, 52, 54, 56, 58 and 59. The torque-transmitting mechanisms50, 52, 54, 56, 58 and 59 are rotating-type torque-transmittingmechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 46. The planet carrier assembly member 26 iscontinuously connected with the sun gear member 32 and the transmissionhousing 60 through the interconnecting member 70. The planet carrierassembly member 36 is continuously connected with the ring gear member44 through the interconnecting member 72.

The sun gear member 22 is selectively connectable with the input shaft17 through the clutch 50. The sun gear member 42 is selectivelyconnectable with the input shaft 17 through the clutch 52. The sun gearmember 22 is selectively connectable with the planet carrier assemblymember 36 through the clutch 54. The ring gear member 24 is selectivelyconnectable with the planet carrier assembly member 36 through theclutch 56. The ring gear member 34 is selectively connectable with thesun gear member 42 through the clutch 58. The ring gear member 34 isselectively connectable with the planet carrier assembly member 46through the clutch 59.

As shown in FIG. 1b, and in particular the truth table disclosedtherein, the torque-transmitting mechanisms are selectively engaged incombinations of three to provide seven forward speed ratios and areverse speed ratio.

The reverse speed ratio is established with the engagement of theclutches 50, 56 and 58. The clutch 50 connects the sun gear member 22 tothe input shaft 17. The clutch 56 connects the ring gear member 24 tothe planet carrier assembly member 36. The clutch 58 connects the ringgear member 34 to the sun gear member 42. The sun gear member 22 rotatesat the same speed as the input shaft 17. The planet carrier assemblymember 26 and the sun gear member 32 do not rotate. The ring gearmembers 24, 44 rotate at the same speed as the planet carrier assemblymember 36. The ring gear member 24 rotates at a speed determined fromthe speed of the sun gear member 22 and the ring gear/sun gear toothratio of the planetary gear set 20. The ring gear member 34 rotates atthe same speed as the sun gear member 42. The planet carrier assemblymember 36 rotates at a speed determined from the speed of the ring gearmember 34 and the ring gear/sun gear tooth ratio of the planetary gearset 30. The planet carrier assembly member 46 rotates at the same speedas the output shaft 19. The planet carrier assembly member 46, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the ring gear member 44, the speed of the sun gear member 42and the ring gear/sun gear tooth ratio of the planetary gear set 40. Thenumerical value of the reverse speed ratio is determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 20, 30 and40.

The first forward speed ratio is established with the engagement of theclutches 50, 52 and 56. The clutch 50 connects the sun gear member 22 tothe input shaft 17. The clutch 52 connects the sun gear member 42 to theinput shaft 17. The clutch 56 connects the ring gear member 24 to theplanet carrier assembly member 36. The sun gear members 22, 42 rotate atthe same speed as the input shaft 17. The planet carrier assembly member26 and the sun gear member 32 do not rotate. The ring gear members 24,44 rotate at the same speed as the planet carrier assembly member 36.The ring gear member 24 rotates at a speed determined from the speed ofthe sun gear member 22 and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The planet carrier assembly member 46 rotates atthe same speed as the output shaft 19. The planet carrier assemblymember 46, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the ring gear member 44, the speed of thesun gear member 42 and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the first forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 20 and 40.

The second forward speed ratio is established with the engagement of theclutches 52, 54 and 56. The clutch 52 connects the sun gear member 42 tothe input shaft 17. The clutch 54 connects the sun gear member 22 to theplanet carrier assembly member 36. The clutch 56 connects the ring gearmember 24 to the planet carrier assembly member 36. The sun gear member22, the ring gear members 24, 44 and the planet carrier assembly member36 rotate at the same speed. The planet carrier assembly member 26 andthe sun gear member 32 do not rotate. The planet carrier assembly member46 rotates at the same speed as the output shaft 19. The sun gear member42 rotates at the same speed as the input shaft 17. The planet carrierassembly member 46, and therefore the output shaft 19, rotates at aspeed determined from the speed of the ring gear member 44, the speed ofthe sun gear member 42 and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the second forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 40.

The third forward speed ratio is established with the engagement of theclutches 52, 54 and 59. The clutch 52 connects the sun gear member 42 tothe input shaft 17. The clutch 54 connects the sun gear member 22 to theplanet carrier assembly member 36. The clutch 59 connects the ring gearmember 34 to the planet carrier assembly member 46. The sun gear member22, the planet carrier assembly member 36 and the ring gear member 44rotate at the same speed. The planet carrier assembly member 26 and thesun gear member 32 do not rotate. The ring gear member 34 and the planetcarrier assembly member 46 rotate at the same speed as the output shaft19. The planet carrier assembly member 36 rotates at a speed determinedfrom the speed of the ring gear member 34 and the ring gear/sun geartooth ratio of the planetary gear set 30. The sun gear member 42 rotatesat the same speed as the input shaft 17. The planet carrier assemblymember 46, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the ring gear member 44, the speed of thesun gear member 42 and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the third forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 30 and 40.

The fourth forward speed ratio is established with the engagement of theclutches 52, 54 and 58. The clutch 52 connects the sun gear member 42 tothe input shaft 17. The clutch 54 connects the sun gear member 22 to theplanet carrier assembly member 36. The clutch 58 connects the ring gearmember 34 to the sun gear member 42. The sun gear member 22, the planetcarrier assembly member 36 and the ring gear member 44 rotate at thesame speed. The planet carrier assembly member 26 and the sun gearmember 32 do not rotate. The ring gear member 34 and the sun gear member42 rotate at the same speed as the input shaft 17. The planet carrierassembly member 36 rotates at a speed determined from the speed of thering gear member 34 and the ring gear/sun gear tooth ratio of theplanetary gear set 30. The planet carrier assembly member 46 rotates atthe same speed as the output shaft 19. The planet carrier assemblymember 46, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the ring gear member 44, the speed of thesun gear member 42 and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the fourth forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 30 and 40.

The fifth forward speed ratio is established with the engagement of theclutches 50, 52 and 54. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

The sixth forward speed ratio is established with the engagement of theclutches 50, 54 and 58. The clutch 50 connects the sun gear member 22 tothe input shaft 17. The clutch 54 connects the sun gear member 22 to theplanet carrier assembly member 36. The clutch 58 connects the ring gearmember 34 to the sun gear member 42. The sun gear member 22, the planetcarrier assembly member 36 and the ring gear member 44 rotate at thesame speed as the input shaft 17. The planet carrier assembly member 26and the sun gear member 32 do not rotate. The ring gear member 34rotates at the same speed as the sun gear member 42. The planet carrierassembly member 36 rotates at a speed determined from the speed of thering gear member 34 and the ring gear/sun gear tooth ratio of theplanetary gear set 30. The planet carrier assembly member 46 rotates atthe same speed as the output shaft 19. The planet carrier assemblymember 46, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the ring gear member 44, the speed of thesun gear member 42 and the ring gear/sun gear tooth ratio of theplanetary gear set 40. The numerical value of the sixth forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 30 and 40.

The seventh forward speed ratio is established with the engagement ofthe clutches 50, 54 and 59. The clutch 50 connects the sun gear member22 to the input shaft 17. The clutch 54 connects the sun gear member 22to the planet carrier assembly member 36. The clutch 59 connects thering gear member 34 to the planet carrier assembly member 46. The sungear member 22, the planet carrier assembly member 36 and the ring gearmember 44 rotate at the same speed as the input shaft 17. The planetcarrier assembly member 26 and the sun gear member 32 do not rotate. Thering gear member 34 and the planet carrier assembly member 46 rotate atthe same speed as the output shaft 19. The ring gear member 34, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the planet carrier assembly member 36 and the ring gear/sungear tooth ratio of the planetary gear set 30. The numerical value ofthe seventh forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 30.

As set forth above, the engagement schedule for the torque-transmittingmechanisms is shown in the truth table of FIG. 1b. This truth table alsoprovides an example of speed ratios that are available utilizing thering gear/sun gear tooth ratios given by way of example in FIG. 1b. TheR1/S1 value is the tooth ratio of the planetary gear set 20; the R2/S2value is the tooth ratio of the planetary gear set 30; and the R3/S3value is the tooth ratio of the planetary gear set 40. Also, the chartof FIG. 1b describes the ratio steps that are attained utilizing thesample of tooth ratios given. For example, the step ratio between thefirst and second forward speed ratios is 2.08, while the step ratiobetween the reverse and first forward ratio is −0.45. It can also bereadily determined from the truth table of FIG. 1b that all of thesingle step forward ratio interchanges are of the single transitionvariety.

FIG. 2a shows a powertrain 110 having a conventional engine and torqueconverter 12, a planetary transmission 114, and a conventional finaldrive mechanism 16.

The planetary transmission 114 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 118, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 118 includesthree planetary gear sets 120, 130 and 140.

The planetary gear set 120 includes a sun gear member 122, a ring gearmember 124, and a planet carrier assembly 126. The planet carrierassembly 126 includes a plurality of pinion gears 127 rotatably mountedon a carrier member 129 and disposed in meshing relationship with boththe sun gear member 122 and the ring gear member 124.

The planetary gear set 130 includes a sun gear member 132, a ring gearmember 134, and a planet carrier assembly member 136. The planet carrierassembly member 136 includes a plurality of pinion gears 137 rotatablymounted on a carrier member 139 and disposed in meshing relationshipwith both the sun gear member 132 and the ring gear member 134.

The planetary gear set 140 includes a sun gear member 142, a ring gearmember 144, and a planet carrier assembly member 146. The planet carrierassembly member 146 includes a plurality of pinion gears 147 rotatablymounted on a carrier member 149 and disposed in meshing relationshipwith both the sun gear member 142 and the ring gear member 144.

The planetary gear arrangement 118 also includes six torque-transmittingmechanisms 150, 152, 154, 156, 158 and 159. The torque-transmittingmechanisms 150, 152, 154, 156, 158 and 159 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 146. The planet carrier assembly member 126 iscontinuously connected with the sun gear member 132 and the transmissionhousing 160 through the interconnecting member 170. The sun gear member122 is continuously connected with the ring gear member 144 through theinterconnecting member 172.

The planet carrier assembly member 136 is selectively connectable withthe input shaft 17 through the clutch 150. The sun gear member 142 isselectively connectable with the input shaft 17 through the clutch 152.The sun gear member 122 is selectively connectable with the planetcarrier assembly member 136 through the clutch 154. The ring gear member124 is selectively connectable with the planet carrier assembly member136 through the clutch 156. The ring gear member 134 is selectivelyconnectable with the sun gear member 142 through the clutch 158. Thering gear member 134 is selectively connectable with the planet carrierassembly member 146 through the clutch 159.

The truth table of FIG. 2b describes the engagement sequence utilized toprovide seven forward speed ratios and three reverse speed ratios in theplanetary gear arrangement 118 shown in FIG. 2a.

The reverse speed ratio (Reverse(2) in FIG. 2b) is established with theengagement of the clutches 150, 156 and 158. The clutch 150 connects theplanet carrier assembly member 136 to the input shaft 17. The clutch 156connects the ring gear member 124 to the planet carrier assembly member136. The clutch 158 connects the ring gear member 134 to the sun gearmember 142. The sun gear member 122 rotates at the same speed as thering gear member 144. The planet carrier assembly member 126 and the sungear member 132 do not rotate. The ring gear member 124 and the planetcarrier assembly member 136 rotate at the same speed as the input shaft17. The sun gear member 122 rotates at a speed determined from the speedof the ring gear member 124 and the ring gear/sun gear tooth ratio ofthe planetary gear set 120. The ring gear member 134 rotates at the samespeed as the sun gear member 142. The ring gear member 134 rotates at aspeed determined from the speed of the planet carrier assembly member136 and the ring gear/sun gear tooth ratio of the planetary gear set130. The planet carrier assembly member 146 rotates at the same speed asthe output shaft 19. The planet carrier assembly member 146, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the ring gear member 144, the speed of the sun gear member 142and the ring gear/sun gear tooth ratio of the planetary gear set 140.The numerical value of the reverse speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 120, 130and 140.

The first forward speed ratio is established with the engagement of theclutches 152, 156 and 159. The clutch 152 connects the sun gear member142 to the input shaft 17. The clutch 156 connects the ring gear member124 to the planet carrier assembly member 136. The clutch 159 connectsthe ring gear member 134 to the planet carrier assembly member 146. Thesun gear member 122 rotates at the same speed as the ring gear member144. The planet carrier assembly member 126 and the sun gear member 132do not rotate. The ring gear member 124 rotates at the same speed as theplanet carrier assembly member 136. The ring gear member 124 rotates ata speed determined from the speed of the sun gear member 122 and thering gear/sun gear tooth ratio of the planetary gear set 120. The ringgear member 134 and the planet carrier assembly member 146 rotate at thesame speed as the output shaft 19. The planet carrier assembly member136 rotates at a speed determined from the speed of the ring gear member134 and the ring gear/sun gear tooth ratio of the planetary gear set130. The sun gear member 142 rotates at the same speed as the inputshaft 17. The planet carrier assembly member 146, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 144, the speed of the sun gear member 142 and the ringgear/sun gear tooth ratio of the planetary gear set 140. The numericalvalue of the first forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 120, 130 and 140.

The second forward speed ratio is established with the engagement of theclutches 152, 154 and 156. The clutch 152 connects the sun gear member142 to the input shaft 17. The clutch 154 connects the planet carrierassembly member 136 to the sun gear member 122. The clutch 156 connectsthe ring gear member 124 to the planet carrier assembly member 136. Thering gear members 124, 144, the sun gear member 122 and the planetcarrier assembly member 136 rotate at the same speed. The planet carrierassembly member 126 and the sun gear member 132 do not rotate. Theplanet carrier assembly member 146 rotates at the same speed as theoutput shaft 19. The sun gear member 142 rotates at the same speed asthe input shaft 17. The planet carrier assembly member 146, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the ring gear member 144, the speed of the sun gear member 142and the ring gear/sun gear tooth ratio of the planetary gear set 140.The numerical value of the second forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set140.

The third forward speed ratio is established with the engagement of theclutches 152, 154 and 159. The clutch 152 connects the sun gear member142 to the input shaft 17. The clutch 154 connects the sun gear member122 to the planet carrier assembly member 136. The clutch 159 connectsthe ring gear member 134 to the planet carrier assembly member 146. Thesun gear member 122, the planet carrier assembly member 136 and the ringgear member 144 rotate at the same speed. The planet carrier assemblymember 126 and the sun gear member 132 do not rotate. The ring gearmember 134 and the planet carrier assembly member 146 rotate at the samespeed as the output shaft 19. The planet carrier assembly member 136rotates at a speed determined from the speed of the ring gear member 134and the ring gear/sun gear tooth ratio of the planetary gear set 130.The sun gear member 142 rotates at the same speed as the input shaft 17.The planet carrier assembly member 146, and therefore the output shaft19, rotates at a speed determined from the speed of the ring gear member144, the speed of the sun gear member 142 and the ring gear/sun geartooth ratio of the planetary gear set 140. The numerical value of thethird forward speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 130 and 140.

The fourth forward speed ratio is established with the engagement of theclutches 152, 154 and 158. The clutch 152 connects the sun gear member142 to the input shaft 17. The clutch 154 connects the sun gear member122 to the planet carrier assembly member 136. The clutch 158 connectsthe ring gear member 134 to the sun gear member 142. The sun gear member122, the planet carrier assembly member 136 and the ring gear member 144rotate at the same speed. The planet carrier assembly member 126 and thesun gear member 132 do not rotate. The ring gear member 134 and the sungear member 142 rotate at the same speed as the input shaft 17. Theplanet carrier assembly member 136 rotates at a speed determined fromthe speed of the ring gear member 134 and the ring gear/sun gear toothratio of the planetary gear set 130. The planet carrier assembly member146 rotates at the same speed as the output shaft 19. The planet carrierassembly member 146, and therefore the output shaft 19, rotates at aspeed determined from the speed of the ring gear member 144, the speedof the sun gear member 142 and the ring gear/sun gear tooth ratio of theplanetary gear set 140. The numerical value of the fourth forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 130 and 140.

The fifth forward speed ratio is established with the engagement of theclutches 150, 152 and 154. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

The sixth forward speed ratio is established with the engagement of theclutches 150, 154 and 158. The clutch 150 connects the planet carrierassembly member 136 to the input shaft 17. The clutch 154 connects theplanet carrier assembly member 136 to the sun gear member 122. Theclutch 158 connects the ring gear member 134 to the sun gear member 142.The sun gear member 122, the ring gear member 144 and the planet carrierassembly member 136 rotate at the same speed as the input shaft 17. Theplanet carrier assembly member 126 and the sun gear member 132 do notrotate. The ring gear member 134 rotates at the same speed as the sungear member 142. The ring gear member 134 rotates at a speed determinedfrom the speed of the planet carrier assembly member 136 and the ringgear/sun gear tooth ratio of the planetary gear set 130. The planetcarrier assembly member 146 rotates at the same speed as the outputshaft 19. The planet carrier assembly member 146, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 144, the speed of the sun gear member 142 and the ringgear/sun gear tooth ratio of the planetary gear set 140. The numericalvalue of the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 130 and 140.

The seventh forward speed ratio is established with the engagement ofthe clutches 150, 158 and 159. The clutch 150 connects the planetcarrier assembly member 136 to the input shaft 17. The clutch 158connects the ring gear member 134 to the sun gear member 142. The clutch159 connects the ring gear member 134 to the planet carrier assemblymember 146. The sun gear member 122 rotates at the same speed as thering gear member 144. The planet carrier assembly member 126 and the sungear member 132 do not rotate. The ring gear member 134, the sun gearmember 142 and the planet carrier assembly member 146 rotate at the samespeed as the output shaft 19. The planet carrier assembly member 136rotates at the same speed as the input shaft 17. The ring gear member134, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the planet carrier assembly member 136 and the ringgear/sun gear tooth ratio of the planetary gear set 130. The numericalvalue of the seventh forward speed ratio is determined utilizing thering gear/sun gear tooth ratio of the planetary gear set 130.

As set forth above, the truth table of FIG. 2b describes the engagementsequence of the torque-transmitting mechanisms utilized to provide threereverse drive ratios and seven forward speed ratios. The truth tablealso provides an example of the ratios that can be attained with thefamily members shown in FIG. 2a utilizing the sample tooth ratios givenin FIG. 2b. The R1/S1 value is the tooth ratio of the planetary gear set120; the R2/S2 value is the tooth ratio of the planetary gear set 130;and the R3/S3 value is the tooth ratio of the planetary gear set 140.Also shown in FIG. 2b are the ratio steps between single step ratios inthe forward direction as well as the reverse to first ratio step ratios.For example, the first to second step ratio is 1.57.

Turning to FIG. 3a, a powertrain 210 includes the engine and torqueconverter 12, a planetary transmission 214, and a final drive mechanism16. The planetary transmission 214 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 218, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 218 includes three planetary gear sets 220, 230 and 240.

The planetary gear set 220 includes a sun gear member 222, a ring gearmember 224, and a planet carrier assembly 226. The planet carrierassembly 226 includes a plurality of pinion gears 227 rotatably mountedon a carrier member 229 and disposed in meshing relationship with boththe sun gear member 222 and the ring gear member 224.

The planetary gear set 230 includes a sun gear member 232, a ring gearmember 234, and a planet carrier assembly member 236. The planet carrierassembly member 236 includes a plurality of pinion gears 237 rotatablymounted on a carrier member 239 and disposed in meshing relationshipwith both the sun gear member 232 and the ring gear member 234.

The planetary gear set 240 includes a sun gear member 242, a ring gearmember 244, and a planet carrier assembly member 246. The planet carrierassembly member 246 includes a plurality of pinion gears 247 rotatablymounted on a carrier member 249 and disposed in meshing relationshipwith both the sun gear member 242 and the ring gear member 244.

The planetary gear arrangement 218 also includes six torque-transmittingmechanisms 250, 252, 254, 256, 258 and 259. The torque-transmittingmechanisms 250, 252, 254, 256, 258 and 259 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 246. The planet carrier assembly member 226 iscontinuously connected with the sun gear member 232 and the transmissionhousing 260 through the interconnecting member 270. The ring gear member224 is continuously connected with the planet carrier assembly member246 through the interconnecting member 272.

The planet carrier assembly member 236 is selectively connectable withthe input shaft 17 through the clutch 250. The ring gear member 244 isselectively connectable with the input shaft 17 through the clutch 252.The planet carrier assembly member 236 is selectively connectable withthe sun gear member 242 through the clutch 254. The ring gear member 224is selectively connectable with the ring gear member 234 through theclutch 256. The sun gear member 222 is selectively connectable with thering gear member 234 through the clutch 258. The ring gear member 234 isselectively connectable with the sun gear member 242 through the clutch259.

As shown in the truth table in FIG. 3b, the torque-transmittingmechanisms are engaged in combinations of three to establish sevenforward speed ratios and one reverse ratio.

The reverse speed ratio is established with the engagement of theclutches 250, 258 and 259. The clutch 250 connects the planet carrierassembly member 236 to the input shaft 17. The clutch 258 connects thesun gear member 222 to the ring gear member 234. The clutch 259 connectsthe ring gear member 234 to the sun gear member 242. The sun gearmembers 222, 242 rotate at the same speed as the ring gear member 234.The planet carrier assembly member 226 and the sun gear member 232 donot rotate. The ring gear member 224 and the planet carrier assemblymember 246 rotate at the same speed as the output shaft 19. The ringgear member 224, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the sun gear member 222 and the ringgear/sun gear tooth ratio of the planetary gear set 220. The planetcarrier assembly member 236 rotates at the same speed as the input shaft17. The ring gear member 234 rotates at a speed determined from thespeed of the planet carrier assembly member 236 and the ring gear/sungear tooth ratio of the planetary gear set 230. The numerical value ofthe reverse speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 220 and 230.

The first forward speed ratio is established with the engagement of theclutches 252, 258 and 259. The clutch 252 connects the ring gear member244 to the input shaft 17. The clutch 258 connects the sun gear member222 to the ring gear member 234. The clutch 259 connects the ring gearmember 234 to the sun gear member 242. The sun gear members 222, 242rotate at the same speed as the ring gear member 234. The planet carrierassembly member 226 and the sun gear member 232 do not rotate. The ringgear member 224 and the planet carrier assembly member 246 rotate at thesame speed as the output shaft 19. The ring gear member 224 rotates at aspeed determined from the speed of the sun gear member 222 and the ringgear/sun gear tooth ratio of the planetary gear set 220. The ring gearmember 244 rotates at the same speed as the input shaft 17. The planetcarrier assembly member 246, and therefore the output shaft 19, rotatesat a speed determined from the speed of the ring gear member 244, thespeed of the sun gear member 242 and the ring gear/sun gear tooth ratioof the planetary gear set 240. The numerical value of the first forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 220 and 240.

The second forward speed ratio is established with the engagement of theclutches 252, 254 and 258. The clutch 252 connects the ring gear member244 to the input shaft 17. The clutch 254 connects the planet carrierassembly member 236 to the sun gear member 242. The clutch 258 connectsthe sun gear member 222 to the ring gear member 234. The sun gear member222 rotates at the same speed as the ring gear member 234. The planetcarrier assembly member 226 and the sun gear member 232 do not rotate.The ring gear member 224 and the planet carrier assembly member 246rotate at the same speed as the output shaft 19. The ring gear member224 rotates at a speed determined from the speed of the sun gear member222 and the ring gear/sun gear tooth ratio of the planetary gear set220. The planet carrier assembly member 236 rotates at the same speed asthe sun gear member 242. The planet carrier assembly member 236 rotatesat a speed determined from the speed of the ring gear member 234 and thering gear/sun gear tooth ratio of the planetary gear set 230. The ringgear member 244 rotates at the same speed as the input shaft 17. Theplanet carrier assembly member 246, and therefore the output shaft 19,rotates at a speed determined from the speed of the ring gear member244, the speed of the sun gear member 242 and the ring gear/sun geartooth ratio of the planetary gear set 240. The numerical value of thesecond forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 220, 230 and 240.

The third forward speed ratio is established with the engagement of theclutches 252, 254 and 259. The clutch 252 connects the ring gear member244 to the input shaft 17. The clutch 254 connects the planet carrierassembly member 236 to the sun gear member 242. The clutch 259 connectsthe ring gear member 234 to the sun gear member 242. The planet carrierassembly member 226 and the sun gear member 232 do not rotate. The ringgear member 224 and the planet carrier assembly member 246 rotate at thesame speed as the output shaft 19. The ring gear member 234, the sungear member 242 and the planet carrier assembly member 236 rotate at thesame speed. The ring gear member 244 rotates at the same speed as theinput shaft 17. The planet carrier assembly member 246, and thereforethe output shaft 19, rotates at a speed determined from the speed of thering gear member 244, the speed of the sun gear member 242 and the ringgear/sun gear tooth ratio of the planetary gear set 240. The numericalvalue of the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 240.

The fourth forward speed ratio is established with the engagement of theclutches 252, 254 and 256. The clutch 252 connects the ring gear member244 to the input shaft 17. The clutch 254 connects the planet carrierassembly member 236 to the sun gear member 242. The clutch 256 connectsthe ring gear member 224 to the ring gear member 234. The planet carrierassembly member 226 and the sun gear member 232 do not rotate. The ringgear members 224, 234 and the planet carrier assembly member 246 rotateat the same speed as the output shaft 19. The planet carrier assemblymember 236 rotates at the same speed as the sun gear member 242. Theplanet carrier assembly member 236 rotates at a speed determined fromthe speed of the ring gear member 234 and the ring gear/sun gear toothratio of the planetary gear set 230. The ring gear member 244 rotates atthe same speed as the input shaft 17. The planet carrier assembly member246, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 244, the speed of the sun gearmember 242 and the ring gear/sun gear tooth ratio of the planetary gearset 240. The numerical value of the fourth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 230 and 240.

The fifth forward speed ratio is established with the engagement of theclutches 252, 256 and 259. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefifth forward speed ratio is 1.

The sixth forward speed ratio is established with the engagement of theclutches 250, 252 and 259. The clutch 250 connects the planet carrierassembly member 236 to the input shaft 17. The clutch 252 connects thering gear member 244 to the input shaft 17. The clutch 259 connects thering gear member 234 to the sun gear member 242. The planet carrierassembly member 226 and the sun gear member 232 do not rotate. The ringgear member 224 and the planet carrier assembly member 246 rotate at thesame speed as the output shaft 19. The planet carrier assembly member236 and the ring gear member 244 rotate at the same speed as the inputshaft 17. The ring gear member 234 rotates at the same speed as the sungear member 242. The ring gear member 234 rotates at a speed determinedfrom the speed of the planet carrier assembly member 236 and the ringgear/sun gear tooth ratio of the planetary gear set 230. The planetcarrier assembly member 246, and therefore the output shaft 19, rotatesat a speed determined from the speed of the ring gear member 244, thespeed of the sun gear member 242 and the ring gear/sun gear tooth ratioof the planetary gear set 240. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 230 and 240.

The seventh forward speed ratio is established with the engagement ofthe clutches 250, 256 and 259. The clutch 250 connects the planetcarrier assembly member 236 to the input shaft 17. The clutch 256connects the ring gear member 224 to the ring gear member 234. Theclutch 259 connects the ring gear member 234 to the sun gear member 242.The planet carrier assembly member 226 and the sun gear member 232 donot rotate. The ring gear member 224 and 234, the sun gear member 242and the planet carrier assembly member 246 rotate at the same speed asthe output shaft 19. The planet carrier assembly member 236 rotates atthe same speed as the input shaft 17. The ring gear member 234, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the planet carrier assembly member 236 and the ring gear/sungear tooth ratio of the planetary gear set 230. The numerical value ofthe seventh forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 230.

As previously set forth, the truth table of FIG. 3b describes thecombinations of engagements utilized for the seven forward speed ratiosand reverse ratio. The truth table also provides an example of speedratios that are available with the family member described above. Theseexamples of speed ratios are determined utilizing the tooth ratios givenin FIG. 3b. The R1/S1 value is the tooth ratio of the planetary gear set220; the R2/S2 value is the tooth ratio of the planetary gear set 230;and the R3/S3 value is the tooth ratio of the planetary gear set 240.Also depicted in FIG. 3b is a chart representing the ratio steps betweenadjacent forward speed ratios and the reverse speed ratio. For example,the first to second ratio interchange has a step of 1.20. It can also bereadily determined from the truth table of FIG. 3b that all of thesingle step forward ratio interchanges are of the single transitionvariety.

A powertrain 310, shown in FIG. 4a, includes the engine and torqueconverter 12, a planetary transmission 314, and the final drivemechanism 16. The planetary transmission 314 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 318, and output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 318 includes three planetary gear sets 320, 330 and 340.

The planetary gear set 320 includes a sun gear member 322, a ring gearmember 324, and a planet carrier assembly member 326. The planet carrierassembly member 326 includes a plurality of pinion gears 327 rotatablymounted on a carrier member 329 and disposed in meshing relationshipwith both the sun gear member 322 and the ring gear member 324.

The planetary gear set 330 includes a sun gear member 332, a ring gearmember 334, and a planet carrier assembly member 336. The planet carrierassembly member 336 includes a plurality of pinion gears 337 rotatablymounted on a carrier member 339 and disposed in meshing relationshipwith both the sun gear member 332 and the ring gear member 334.

The planetary gear set 340 includes a sun gear member 342, a ring gearmember 344, and a planet carrier assembly member 346. The planet carrierassembly member 346 includes a plurality of pinion gears 347 rotatablymounted on a carrier member 349 and disposed in meshing relationshipwith both the sun gear member 342 and the ring gear member 344.

The planetary gear arrangement 318 also includes six torque-transmittingmechanisms 350, 352, 354, 356, 358 and 359. The torque-transmittingmechanisms 350, 352, 354, 356, 358 and 359 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 346. The planet carrier assembly member 326 iscontinuously connected with the sun gear member 332 and the transmissionhousing 360 through the interconnecting member 370. The ring gear member324 is continuously connected with the planet carrier assembly member346 through the interconnecting member 372.

The planet carrier assembly member 336 is selectively connectable withthe input shaft 17 through the clutch 350. The ring gear member 344 isselectively connectable with the input shaft 17 through the clutch 352.The sun gear member 322 is selectively connectable with the planetcarrier assembly member 336 through the clutch 354. The sun gear member342 is selectively connectable with the planet carrier assembly member336 through the clutch 356. The ring gear member 324 is selectivelyconnectable with the ring gear member 334 through the clutch 358. Thering gear member 334 is selectively connectable with the sun gear member342 through the clutch 359.

The truth tables given in FIGS. 4b, 5 b, 6 b, 7 b, 8 b, 9 b, 10 b, 11 b,12 b and 13 b show the engagement sequences for the torque-transmittingmechanisms to provide at least seven forward speed ratios and at leastone reverse ratio. As shown and described above for the configuration inFIGS. 1a, 2 a and 3 a, those skilled in the art will understand from therespective truth tables how the speed ratios are established through theplanetary gear sets identified in the written description.

The truth table shown in FIG. 4b describes the engagement combinationand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 4b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 4b. The R1/S1 value is the tooth ratio for the planetary gear set320; the R2/S2 value is the tooth ratio for the planetary gear set 330;and the R3/S3 value is the tooth ratio for the planetary gear set 340.Also given in FIG. 4b is a chart describing the step ratios between theadjacent forward speed ratios and the reverse to first forward speedratio. For example, the first to second forward speed ratio step is1.31. It can be readily determined from the truth table of FIG. 4b thateach of the forward single step ratio interchanges is a singletransition shift.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 320. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 320, 330 and 340. The numerical valueof the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 320 and 340. Thenumerical value of the third forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 340. Thenumerical values of the fourth and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 330 and 340. The numerical value of the fifthforward speed ratio is 1. The numerical value of the seventh forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear set 330.

A powertrain 410, shown in FIG. 5a, includes the engine and torqueconverter 12, a planetary transmission 414 and the final drive mechanism16. The planetary transmission 414 includes a planetary gear arrangement418, input shaft 17 and output shaft 19. The planetary gear arrangement418 includes three simple planetary gear sets 420, 430 and 440.

The planetary gear set 420 includes a sun gear member 422, a ring gearmember 424, and a planet carrier assembly 426. The planet carrierassembly 426 includes a plurality of pinion gears 427 rotatably mountedon a carrier member 429 and disposed in meshing relationship with boththe sun gear member 422 and the ring gear member 424.

The planetary gear set 430 includes a sun gear member 432, a ring gearmember 434, and a planet carrier assembly member 436. The planet carrierassembly member 436 includes a plurality of pinion gears 437 rotatablymounted on a carrier member 439 and disposed in meshing relationshipwith both the sun gear member 432 and the ring gear member 434.

The planetary gear set 440 includes a sun gear member 442, a ring gearmember 444, and a planet carrier assembly member 446. The planet carrierassembly member 446 includes a plurality of pinion gears 447 rotatablymounted on a carrier member 449 and disposed in meshing relationshipwith both the sun gear member 442 and the ring gear member 444.

The planetary gear arrangement 418 also includes six torque-transmittingmechanisms 450, 452, 454, 456, 458 and 459. The torque-transmittingmechanisms 450, 452, 454, 456, 458 and 459 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the ring gearmember 444. The sun gear member 422 is continuously connected with theplanet carrier assembly member 436 and the transmission housing 460through the interconnecting member 470. The ring gear member 434 iscontinuously connected with the sun gear member 442 through theinterconnecting member 472.

The sun gear member 442 is selectively connectable with the input shaft17 through the clutch 450. The planet carrier assembly member 446 isselectively connectable with the input shaft 17 through the clutch 452.The ring gear member 424 is selectively connectable with the ring gearmember 434 through the clutch 454. The ring gear member 424 isselectively connectable with the sun gear member 432 through the clutch456. The ring gear member 424 is selectively connectable with the planetcarrier assembly member 446 through the clutch 458. The planet carrierassembly member 426 is selectively connectable with the ring gear member444 through the clutch 459.

The truth table shown in FIG. 5b describes the engagement combinationand sequence of the torque-transmitting mechanisms 450, 452, 454, 456,458 and 459 that are employed to provide the reverse drive ratio and theseven forward speed ratios. It should be noted that thetorque-transmitting mechanisms 450 and 459 are engaged through theneutral condition to simplify the forward/reverse interchange.

Also given in the truth table of FIG. 5b is a set of numerical valuesthat are attainable with the present invention utilizing the ringgear/sun gear tooth ratios shown. The R1/S1 value is the tooth ratio ofthe planetary gear set 420; the R2/S2 value is the tooth ratio of theplanetary gear set 430; and the R3/S3 value is the tooth ratio of theplanetary gear set 440. As can also be determined from the truth tableof FIG. 5b, the single step forward interchanges are single transitionshifts.

FIG. 5b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.89. Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 420 and 430. The numericalvalues of the first and third forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets420 and 440. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 420. The numerical value of the fourth forward speed ratiois 1. The numerical value of the fifth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set440. The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets430 and 440. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 420, 430 and 440.

A powertrain 510, shown in FIG. 6a, includes an engine and torqueconverter 12, a planetary gear transmission 514 and the final drivemechanism 16. The planetary transmission 514 includes the input shaft17, a planetary gear arrangement 518 and the output shaft 19. Theplanetary gear arrangement 518 includes three planetary gear sets 520,530 and 540.

The planetary gear set 520 includes a sun gear member 522, a ring gearmember 524, and a planet carrier assembly 526. The planet carrierassembly 526 includes a plurality of pinion gears 527 rotatably mountedon a carrier member 529 and disposed in meshing relationship with boththe sun gear member 522 and the ring gear member 524.

The planetary gear set 530 includes a sun gear member 532, a ring gearmember 534, and a planet carrier assembly member 536. The planet carrierassembly member 536 includes a plurality of pinion gears 537 rotatablymounted on a carrier member 539 and disposed in meshing relationshipwith both the sun gear member 532 and the ring gear member 534.

The planetary gear set 540 includes a sun gear member 542, a ring gearmember 544, and a planet carrier assembly member 546. The planet carrierassembly member 546 includes a plurality of pinion gears 547 rotatablymounted on a carrier member 549 and disposed in meshing relationshipwith both the sun gear member 542 and the ring gear member 544.

The planetary gear arrangement 518 also includes six torque-transmittingmechanisms 550, 552, 554, 556, 558 and 559. The torque-transmittingmechanisms 550, 552, 554, 556, 558 and 559 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 536. The ring gear member 524 is continuouslyconnected with the ring gear member 534 and the transmission housing 560through the interconnecting member 570. The sun gear member 532 iscontinuously connected with the planet carrier assembly member 546through the interconnecting member 572.

The planet carrier assembly member 526 is selectively connectable withthe input shaft 17 through the clutch 550. The sun gear member 542 isselectively connectable with the input shaft 17 through the clutch 552.The planet carrier assembly member 526 is selectively connectable withthe sun gear member 532 through the clutch 554. The planet carrierassembly member 526 is selectively connectable with the planet carrierassembly member 536 through the clutch 556. The sun gear member 522 isselectively connectable with the sun gear member 542 through the clutch558. The sun gear member 522 is selectively connectable with the ringgear member 544 through the clutch 559.

The truth table shown in FIG. 6b describes the engagement sequence andcombination of the torque-transmitting mechanisms to provide one reversespeed ratios and seven forward speed ratios. It should be noted that thetorque-transmitting mechanisms 552 and 554 can remain engaged throughthe neutral condition, thereby simplifying the forward/reverseinterchange. It can also be determined from the truth table of FIG. 6bthat all of the single and double step forward ratio interchanges are ofthe single transition variety. The chart of FIG. 6b describes the ratiosteps between adjacent forward speed ratios and the ratio step betweenthe reverse and first forward speed ratio.

Those skilled in the art, upon reviewing the truth table and theschematic representation of FIG. 6a, can determine that the numericalvalues of the reverse, fourth and fifth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 520, 530 and 540. The numerical values of the firstand seventh forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 520 and 530. Thenumerical value of the second forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set520. The numerical value of the third forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set530. The numerical value of the sixth forward speed ratio is 1.

The sample speed ratios given in the truth table are determinedutilizing the tooth ratio values also given in FIG. 6b. The R1/S1 valueis the tooth ratio of the planetary gear set 520; the R2/S2 value is thetooth ratio of the planetary gear set 530; and the R3/S3 value is thetooth ratio of the planetary gear set 540.

A powertrain 610, shown in FIG. 7a, has the engine and torque converter12, a planetary transmission 614 and the final drive mechanism 16. Theplanetary transmission 614 includes the input shaft 17, a planetary geararrangement 618 and the output shaft 19. The planetary gear arrangement618 includes three planetary gear sets 620, 630 and 640.

The planetary gear set 620 includes a sun gear member 622, a ring gearmember 624, and a planet carrier assembly 626. The planet carrierassembly 626 includes a plurality of pinion gears 627 rotatably mountedon a carrier member 629 and disposed in meshing relationship with boththe sun gear member 622 and the ring gear member 624.

The planetary gear set 630 includes a sun gear member 632, a ring gearmember 634, and a planet carrier assembly member 636. The planet carrierassembly member 636 includes a plurality of pinion gears 637 rotatablymounted on a carrier member 639 and disposed in meshing relationshipwith both the sun gear member 632 and the ring gear member 634.

The planetary gear set 640 includes a sun gear member 642, a ring gearmember 644, and a planet carrier assembly member 646. The planet carrierassembly member 646 includes a plurality of pinion gears 647 rotatablymounted on a carrier member 649 and disposed in meshing relationshipwith both the sun gear member 642 and the ring gear member 644.

The planetary gear arrangement 618 also includes six torque-transmittingmechanisms 650, 652, 654, 656, 658 and 659. The torque-transmittingmechanisms 650, 652, 654, 656, 658 and 659 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 646. The planet carrier assembly member 626 iscontinuously connected with the sun gear member 632 and the transmissionhousing 660 through the interconnecting member 670. The planet carrierassembly member 636 is continuously connected with the ring gear member644 through the interconnecting member 672.

The ring gear member 624 is selectively connectable with the input shaft17 through the clutch 650. The sun gear member 622 is selectivelyconnectable with the input shaft 17 through the clutch 652. The sun gearmember 642 is selectively connectable with the input shaft 17 throughthe clutch 654. The ring gear member 624 is selectively connectable withthe planet carrier assembly member 636 through the clutch 656. The ringgear member 624 is selectively connectable with the ring gear member 634through the clutch 658. The ring gear member 634 is selectivelyconnectable with the planet carrier assembly member 646 through theclutch 659.

The truth table shown in FIG. 7b describes the combination oftorque-transmitting mechanism engagements that will provide the tworeverse drive ratios and seven forward speed ratios, as well as thesequence of these engagements and interchanges. The torque-transmittingmechanisms 652 and 656 can be engaged through the neutral condition,thereby simplifying the forward/reverse interchange.

The ratio values given are by way of example and are establishedutilizing the ring gear/sun gear tooth ratios given in FIG. 7b. Forexample, the R1/S1 value is the tooth ratio of the planetary gear set620; the R2/S2 value is the tooth ratio of the planetary gear set 630;and the R3/S3 value is the tooth ratio of the planetary gear set 640.The ratio steps between adjacent forward ratios and the reverse to firstratio are also given in FIG. 7b.

Those skilled in the art will, upon reviewing the truth table of FIG.7b, recognize that numerical value of the reverse speed ratio (Reverse2) is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 620. The numerical value of the first forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 620 and 640. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 620, 630 and 640. The numerical valueof the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 640. The numericalvalues of the fourth and fifth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear set630 and 640. The numerical value of the sixth forward speed ratio is 1.The numerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set630.

A powertrain 710, shown in FIG. 8a, has the conventional engine andtorque converter 12, a planetary transmission 714, and the conventionalfinal drive mechanism 16. The engine and torque converter 12 aredrivingly connected with the planetary transmission 714 through theinput shaft 17. The planetary transmission 714 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 714 includes a planetary gear arrangement 718that has a first planetary gear set 720, a second planetary gear set730, and a third planetary gear set 740.

The planetary gear set 720 includes a sun gear member 722, a ring gearmember 724, and a planet carrier assembly 726. The planet carrierassembly 726 includes a plurality of pinion gears 727 rotatably mountedon a carrier member 729 and disposed in meshing relationship with boththe sun gear member 722 and the ring gear member 724.

The planetary gear set 730 includes a sun gear member 732, a ring gearmember 734, and a planet carrier assembly member 736. The planet carrierassembly member 736 includes a plurality of pinion gears 737 rotatablymounted on a carrier member 739 and disposed in meshing relationshipwith both the sun gear member 732 and the ring gear member 734.

The planetary gear set 740 includes a sun gear member 742, a ring gearmember 744, and a planet carrier assembly member 746. The planet carrierassembly member 746 includes a plurality of pinion gears 747 rotatablymounted on a carrier member 749 and disposed in meshing relationshipwith both the sun gear member 742 and the ring gear member 744.

The planetary gear arrangement 718 also includes six torque-transmittingmechanisms 750, 752, 754, 756, 758 and 759. The torque-transmittingmechanisms 750, 752, 754, 756, 758 and 759 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 736. The ring gear member 724 is continuouslyconnected with the ring gear member 734 and the transmission housing 760through the interconnecting member 770. The sun gear member 732 iscontinuously connected with the sun gear member 742 through theinterconnecting member 772.

The planet carrier assembly member 726 is selectively connectable withthe input shaft 17 through the clutch 750. The ring gear member 744 isselectively connectable with the input shaft 17 through the clutch 752.The planet carrier assembly member 726 is selectively connectable withthe planet carrier assembly member 746 through the clutch 754. The sungear member 722 is selectively connectable with the planet carrierassembly member 736 through the clutch 756. The sun gear member 722 isselectively connectable with the planet carrier assembly member 746through the clutch 758. The planet carrier assembly member 736 isselectively connectable with the ring gear member 744 through the clutch759.

The truth table of FIG. 8b defines the torque-transmitting mechanismengagement sequence utilized for each of the forward speed ratios andthe reverse speed ratio. Also given in the truth table is a set ofnumerical values that are attainable with the present inventionutilizing the ring gear/sun gear tooth ratios given in FIG. 8b. TheR1/S1 value is the tooth ratio of the planetary gear set 720; the R2/S2value is the tooth ratio of the planetary gear set 730; and the R3/S3value is the tooth ratio of the planetary gear set 740. As can also bedetermined from the truth table of FIG. 8b, the single step forwardinterchanges are single transition shifts, as are the double stepinterchanges in the forward direction.

FIG. 8b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.72. Those skilled in the art will recognize that the numerical valuesof the reverse, second and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets730 and 740. The numerical value of the first forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 730. The numerical value of the third forward speed ratio is 1.The numerical values of the fourth and fifth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 720, 730 and 740. The numerical value of the sixthforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 720.

A powertrain 810, shown in FIG. 9a, has the conventional engine andtorque converter 12, a planetary transmission 814, and the final drivemechanism 16. The engine and torque converter 12 are drivingly connectedwith the planetary transmission 814 through the input shaft 17. Theplanetary transmission 814 is drivingly connected with the final drivemechanism 16 through the output shaft 19. The planetary transmission 814includes a planetary gear arrangement 818 that has a first planetarygear set 820, a second planetary gear set 830, and a third planetarygear set 840.

The planetary gear set 820 includes a sun gear member 822, a ring gearmember 824, and a planet carrier assembly 826. The planet carrierassembly 826 includes a plurality of pinion gears 827 rotatably mountedon a carrier member 829 and disposed in meshing relationship with boththe sun gear member 822 and the ring gear member 824.

The planetary gear set 830 includes a sun gear member 832, a ring gearmember 834, and a planet carrier assembly member 836. The planet carrierassembly member 836 includes a plurality of pinion gears 837 rotatablymounted on a carrier member 839 and disposed in meshing relationshipwith both the sun gear member 832 and the ring gear member 834.

The planetary gear set 840 includes a sun gear member 842, a ring gearmember 844, and a planet carrier assembly member 846. The planet carrierassembly member 846 includes a plurality of pinion gears 847 rotatablymounted on a carrier member 849 and disposed in meshing relationshipwith both the sun gear member 842 and the ring gear member 844.

The planetary gear arrangement 818 also includes six torque-transmittingmechanisms 850, 852, 854, 856, 858 and 859. The torque-transmittingmechanisms 850, 852, 854, 856, 858 and 859 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the ring gearmember 844. The sun gear member 822 is continuously connected with thering gear member 834 and the transmission housing 860 through theinterconnecting member 870. The ring gear member 824 is continuouslyconnected with the sun gear member 842 through the interconnectingmember 872.

The ring gear member 824 is selectively connectable with the input shaft17 through the clutch 850. The planet carrier assembly member 826 isselectively connectable with the input shaft 17 through the clutch 852.The ring gear member 824 is selectively connectable with the planetcarrier assembly member 836 through the clutch 854. The planet carrierassembly member 826 is selectively connectable with the planet carrierassembly member 836 through the clutch 856. The planet carrier assemblymember 836 is selectively connectable with the planet carrier assemblymember 846 through the clutch 858. The sun gear member 832 isselectively connectable with the ring gear member 844 through the clutch859.

The truth table shown in FIG. 9b defines the torque-transmittingmechanism engagement sequence that provides the reverse speed ratio andseven forward speed ratios shown in the truth table and available withthe planetary gear arrangement 818. The truth table indicates that thetorque-transmitting mechanisms 850 and 858 can remain engaged throughthe neutral condition, thereby simplifying the forward/reverseinterchange. A sample of numerical values for the individual ratios isalso given in the truth table of FIG. 9b. These numerical values havebeen calculated using the ring gear/sun gear tooth ratios also given byway of example in FIG. 9b. The R1/S1 value is the tooth ratio of theplanetary gear set 820; the R2/S2 value is the tooth ratio of theplanetary gear set 830; and the R3/S3 value is the tooth ratio of theplanetary gear set 840. FIG. 9b also describes the ratio steps betweenadjacent forward ratios and between the reverse and first forward ratio.For example, the ratio step between the first and second forward ratiosis 1.44.

Those skilled in the art of planetary transmissions will recognize thatthe numerical value of the reverse speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 830 and840. The numerical values of the first and second forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 820 and 840. The numerical value of the thirdforward speed ratio is 1. The numerical value of the fourth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear set 820. The numerical values of the fifth andseventh forward speed ratios are determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 820 and 830. The numericalvalue of the sixth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 830.

The powertrain 910, shown in FIG. 10a, includes the conventional engineand torque converter 12, a planetary transmission 914, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 914 throughthe input shaft 17. The planetary transmission 914 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 914 includes a planetary gear arrangement 918that has a first planetary gear set 920, a second planetary gear set930, and a third planetary gear set 940.

The planetary gear set 920 includes a sun gear member 922, a ring gearmember 924, and a planet carrier assembly 926. The planet carrierassembly 926 includes a plurality of pinion gears 927 that are rotatablymounted on a carrier member 929 and disposed in meshing relationshipwith the sun gear member 922 and the ring gear member 924, respectively.

The planetary gear set 930 includes a sun gear member 932, a ring gearmember 934, and a planet carrier assembly member 936. The planet carrierassembly member 936 includes a plurality of pinion gears 937 rotatablymounted on a carrier member 939 and disposed in meshing relationshipwith both the sun gear member 932 and the ring gear member 934.

The planetary gear set 940 includes a sun gear member 942, a ring gearmember 944, and a planet carrier assembly member 946. The planet carrierassembly member 946 includes a plurality of pinion gears 947 rotatablymounted on a carrier member 949 and disposed in meshing relationshipwith both the sun gear member 942 and the ring gear member 944.

The planetary gear arrangement 918 also includes six torque-transmittingmechanisms 950, 952, 954, 956, 958 and 959. The torque-transmittingmechanisms 950, 952, 954, 956, 958 and 959 are rotating-typetorque-transmitting mechanisms, commonly termed clutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 946. The ring gear member 924 is continuouslyconnected with the ring gear member 934 and the transmission housing 960through the interconnecting member 970. The sun gear member 932 iscontinuously connected with the planet carrier assembly member 946through the interconnecting member 972.

The planet carrier assembly member 926 is selectively connectable withthe input shaft 17 through the clutch 950. The sun gear member 942 isselectively connectable with the input shaft 17 through the clutch 952.The planet carrier assembly member 926 is selectively connectable withthe sun gear member 932 through the clutch 954. The planet carrierassembly member 926 is selectively connectable with the planet carrierassembly member 936 through the clutch 956. The sun gear member 922 isselectively connectable with the sun gear member 942 through the clutch958. The sun gear member 922 is selectively connectable with the ringgear member 944 through the clutch 959.

The truth table of FIG. 10b describes the torque-transmitting mechanismengagement sequence utilized to provide the reverse speed ratio andseven forward speed ratios. The truth table also provides a set ofexamples for the ratios for each of the reverse and forward speedratios. These numerical values have been determined utilizing the ringgear/sun gear tooth ratios given in FIG. 10b. The R1/S1 value is thetooth ratio of the planetary gear set 920; the R2/S2 value is the toothratio of the planetary gear set 930; and the R3/S3 value is the toothratio of the planetary gear set 940.

Those skilled in the art, upon reviewing the engagement combinations,will recognize that the numerical values of the reverse and fifthforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 920 and 940. The numericalvalues of the first and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set920. The numerical value of the second forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets920 and 930. The numerical value of the third forward speed ratio is 1.The numerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets920, 930 and 940. The numerical value of the sixth forward speed ratiois determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 930.

A powertrain 1010, shown in FIG. 11a, includes the conventional engineand torque converter 12, a planetary transmission 1014, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1014 through theinput shaft 17. The planetary transmission 1014 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1014 includes a planetary gear arrangement 1018that has a first planetary gear set 1020, a second planetary gear set1030, and a third planetary gear set 1040.

The planetary gear set 1020 includes a sun gear member 1022, a ring gearmember 1024, and a planet carrier assembly 1026. The planet carrierassembly 1026 includes a plurality of pinion gears 1027 rotatablymounted on a carrier member 1029 and disposed in meshing relationshipwith both the sun gear member 1022 and the ring gear member 1024.

The planetary gear set 1030 includes a sun gear member 1032, a ring gearmember 1034, and a planet carrier assembly member 1036. The planetcarrier assembly member 1036 includes a plurality of pinion gears 1037rotatably mounted on a carrier member 1039 and disposed in meshingrelationship with both the sun gear member 1032 and the ring gear member1034.

The planetary gear set 1040 includes a sun gear member 1042, a ring gearmember 1044, and a planet carrier assembly member 1046. The planetcarrier assembly member 1046 includes a plurality of pinion gears 1047rotatably mounted on a carrier member 1049 and disposed in meshingrelationship with both the sun gear member 1042 and the ring gear member1044.

The planetary gear arrangement 1018 also includes sixtorque-transmitting mechanisms 1050, 1052, 1054, 1056, 1058 and 1059.The torque-transmitting mechanisms 1050, 1052, 1054, 1056, 1058 and 1059are rotating-type torque-transmitting mechanisms, commonly termedclutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the ring gearmember 1044. The ring gear member 1024 is continuously connected withthe sun gear member 1032 and the transmission housing 1060 through theinterconnecting member 1070. The ring gear member 1034 is continuouslyconnected with the sun gear member 1042 through the interconnectingmember 1072.

The ring gear member 1034 is selectively connectable with the inputshaft 17 through the clutch 1050. The planet carrier assembly member1036 is selectively connectable with the input shaft 17 through theclutch 1052. The sun gear member 1022 is selectively connectable withthe planet carrier assembly member 1046 through the clutch 1054. The sungear member 1022 is selectively connectable with the ring gear member1044 through the clutch 1056. The planet carrier assembly member 1026 isselectively connectable with the planet carrier assembly member 1036through the clutch 1058. The planet carrier assembly member 1026 isselectively connectable with the planet carrier assembly member 1046through the clutch 1059.

The truth table shown in FIG. 11b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the eight forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 11b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 11b. The R1/S1 value is the tooth ratio for the planetary gearset 1020; the R2/S2 value is the tooth ratio for the planetary gear set1030; and the R3/S3 value is the tooth ratio for the planetary gear set1040. Also given in FIG. 11b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1040. The numerical values of the firstand second forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1030 and 1040. Thenumerical value of the third forward speed ratio is 1. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 1030. The numericalvalue of the fifth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1020 and 1030. Thenumerical values of the sixth and eighth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1020, 1030 and 1040. The numerical value of theseventh forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1020.

A powertrain 1110, shown in FIG. 12a, has a conventional engine andtorque converter 12, a planetary transmission 1114, and the conventionalfinal drive mechanism 16. The planetary transmission 1114 includes aplanetary gear arrangement 1118 which is connected with the engine andtorque converter 12 through the input shaft 17 and with the final drivemechanism 16 through the output shaft 19. The planetary gear arrangement1118 includes three planetary gear sets 1120, 1130 and 1140.

The planetary gear set 1120 includes a sun gear member 1122, a ring gearmember 1124, and a planet carrier assembly 1126. The planet carrierassembly 1126 includes a plurality of pinion gears 1127 rotatablymounted on a carrier member 1129 and disposed in meshing relationshipwith both the sun gear member 1122 and the ring gear member 1124.

The planetary gear set 1130 includes a sun gear member 1132, a ring gearmember 1134, and a planet carrier assembly member 1136. The planetcarrier assembly member 1136 includes a plurality of intermeshing piniongears 1137 that are rotatably mounted on a carrier member 1139 anddisposed in meshing relationship with both the sun gear member 1132 andthe ring gear member 1134.

The planetary gear set 1140 includes a sun gear member 1142, a ring gearmember 1144, and a planet carrier assembly member 1146. The planetcarrier assembly member 1146 includes a plurality of pinion gears 1147rotatably mounted on a carrier member 1149 and disposed in meshingrelationship with both the sun gear member 1142 and the ring gear member1144.

The planetary gear arrangement 1118 also includes sixtorque-transmitting mechanisms 1150, 1152, 1154, 1156, 1158 and 1159.The torque-transmitting mechanisms 1150, 1152, 1154, 1156, 1158 and 1159are rotating-type torque-transmitting mechanisms, commonly termedclutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the sun gearmember 1142. The ring gear member 1124 is continuously connected withthe sun gear member 1132 and the transmission housing 1160 through theinterconnecting member 1170. The ring gear member 1134 is continuouslyconnected with the planet carrier assembly member 1146 through theinterconnecting member 1172.

The ring gear member 1134 is selectively connectable with the inputshaft 17 through the clutch 1150. The planet carrier assembly member1136 is selectively connectable with the input shaft 17 through theclutch 1152. The ring gear member 1144 is selectively connectable withthe input shaft 17 through the clutch 1154. The sun gear member 1122 isselectively connectable with the planet carrier assembly member 1136through the clutch 1156. The sun gear member 1122 is selectivelyconnectable with the sun gear member 1142 through the clutch 1158. Theplanet carrier assembly member 1126 is selectively connectable with theplanet carrier assembly member 1136 through the clutch 1159.

The truth table shown in FIG. 12b describes the engagement sequence andengagement combinations utilized with the present family member toprovide the reverse drive ratio and seven forward speed ratios. Thetruth table of FIG. 12b also provides a set of example numbers that canbe established in the planetary gear arrangement 1118 utilizing the ringgear/sun gear tooth ratios. The R1/S1 value is the ring gear/sun geartooth ratio of the planetary gear set 1120; the R2/S2 value is the ringgear/sun gear tooth ratio of the planetary gear set 1130; and the R3/S3value is the ring gear/sun gear tooth ratio of the planetary gear set1140.

The chart of FIG. 12b describes the ratio steps between adjacent forwardspeed ratios for a seven-speed transmission. These step ratios areestablished utilizing the example speed ratios given in the truth table.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1140. The numerical values of the firstand seventh forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1130 and 1140. Thenumerical value of the second forward speed ratio is determinedutilizing the-ring gear/sun gear tooth ratio of the planetary gear set1130. The numerical value of the third forward speed ratio is 1. Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1120 and 1130. The numerical value of the fifth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1120, 1130 and 1140. The numerical value of thesixth forward speed ratio is determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 1120.

A powertrain 1210, shown in FIG. 13a, includes the conventional engineand torque converter 12, a planetary transmission 1214, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1214 through theinput shaft 17. The planetary transmission 1214 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1214 includes a planetary gear arrangement 1218that has a first planetary gear set 1220, a second planetary gear set1230, and a third planetary gear set 1240.

The planetary gear set 1220 includes a sun gear member 1222, a ring gearmember 1224, and a planet carrier assembly 1226. The planet carrierassembly 1226 includes a plurality of pinion gears 1227 rotatablymounted on a carrier member 1229 and disposed in meshing relationshipwith both the sun gear member 1222 and the ring gear member 1224.

The planetary gear set 1230 includes a sun gear member 1232, a ring gearmember 1234, and a planet carrier assembly member 1236. The planetcarrier assembly member 1236 includes a plurality of pinion gears 1237rotatably mounted on a carrier member 1239 and disposed in meshingrelationship with both the sun gear member 1232 and the ring gear member1234.

The planetary gear set 1240 includes a sun gear member 1242, a ring gearmember 1244, and a planet carrier assembly member 1246. The planetcarrier assembly member 1246 includes a plurality of pinion gears 1247and 1248 rotatably mounted on a carrier member 1249 and disposed inmeshing relationship with both the sun gear member 1242 and the ringgear member 1244.

The planetary gear arrangement 1218 also includes sixtorque-transmitting mechanisms 1250, 1252, 1254, 1256, 1258 and 1259.The torque-transmitting mechanisms 1250, 1252, 1254, 1256, 1258 and 1259are rotating-type torque-transmitting mechanisms, commonly termedclutches.

The input shaft 17 is not continuously connected with any planetary gearmember. The output shaft 19 is continuously connected with the planetcarrier assembly member 1246. The sun gear member 1222 is continuouslyconnected with the ring gear member 1234 and the transmission housing1260 through the interconnecting member 1270. The sun gear member 1232is continuously connected with the ring gear member 1244 through theinterconnecting member 1272.

The ring gear member 1224 is selectively connectable with the inputshaft 17 through the clutch 1250. The sun gear member 1242 isselectively connectable with the input shaft 17 through the clutch 1252.The planet carrier assembly member 1226 is selectively connectable withthe sun gear member 1232 through the clutch 1254. The planet carrierassembly member 1226 is selectively connectable with the planet carrierassembly member 1236 through the clutch 1256. The planet carrierassembly member 1226 is selectively connectable with the sun gear member1242 through the clutch 1258. The sun gear member 1232 is selectivelyconnectable with the sun gear member 1242 through the clutch 1259.

The truth table shown in FIG. 13b describes the engagement combinationsand the engagement sequence necessary to provide a reverse speed ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 13b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 13b. The R1/S1 value is the tooth ratio for the planetary gear set1220; the R2/S2 value is the tooth ratio for the planetary gear set1230; and the R3/S3 value is the tooth ratio for the planetary gear set1240. Also given in FIG. 13b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1240. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1220 and 1240. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1220. The numerical value ofthe third forward speed ratio is 1. The numerical value of the fourthforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1220 and 1230. The numerical values ofthe fifth and sixth forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 1220, 1230and 1240. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1230 and 1240.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

What is claimed is:
 1. A multi-speed transmission comprising: an inputshaft; an output shaft; first, second and third planetary gear sets eachhaving first, second and third members; said output shaft beingcontinuously interconnected with a member of said planetary gear sets; afirst interconnecting member continuously interconnecting said firstmember of said first planetary gear set with said first member of saidsecond planetary gear set and a stationary member; a secondinterconnecting member continuously interconnecting said second memberof said second planetary gear set with said first member of said thirdplanetary gear set; a first torque-transmitting mechanism selectivelyinterconnecting a member of said first, or third planetary gear set withsaid input shaft; a second torque-transmitting mechanism selectivelyinterconnecting a member of said, second or third planetary gear setwith said input shaft; a third torque-transmitting mechanism selectivelyinterconnecting a member of said first or second planetary gear set withsaid input shaft or with a member of said third planetary gear set; afourth torque-transmitting mechanism selectively interconnecting amember of said first planetary gear set with a member of said second orthird planetary gear set; a fifth torque-transmitting mechanismselectively interconnecting a member of said third planetary gear setwith a member of said first or second planetary gear set; and a sixthtorque-transmitting mechanism selectively interconnecting a member ofsaid first, second or third planetary gear set with another member ofsaid first, second or third planetary gear set, the pair of membersinterconnected by said sixth torque-transmitting mechanism beingdifferent from the members interconnected with said input shaft by saidfirst, second and third torque-transmitting mechanisms, respectively,and from the pairs of members interconnected by said third, fourth andfifth torque-transmitting mechanisms, respectively; saidtorque-transmitting mechanisms being engaged in combinations of three toestablish at least seven forward speed ratios and at least one reversespeed ratio between said input shaft and said output shaft.
 2. Thetransmission defined in claim 1, wherein said first, second, third,fourth, fifth and sixth torque-transmitting mechanisms compriseclutches.
 3. The transmission defined in claim 1, wherein each of saidplanetary gear sets includes a planet carrier assembly member, andwherein said planet carrier assembly member of each of said planetarygear sets is a single-pinion carrier.
 4. The transmission defined inclaim 1, wherein each of said planetary gear sets includes a planetcarrier assembly member, and wherein at least one planet carrierassembly member of one of said planetary gear sets is a double-pinioncarrier.
 5. A multi-speed transmission comprising: an input shaft; anoutput shaft; a planetary gear arrangement having first, second andthird planetary gear sets, each planetary gear set having first, secondand third members; said output shaft being continuously interconnectedwith a member of said planetary gear sets; a first interconnectingmember continuously interconnecting said first member of said firstplanetary gear set with said first member of said second planetary gearset and a stationary member; a second interconnecting membercontinuously interconnecting said second member of said second planetarygear set with said first member of said third planetary gear set; andsix torque-transmitting mechanisms for selectively interconnecting saidmembers of said first, second or third planetary gear sets with saidinput shaft, or with other members of said planetary gear sets in pairsfor common rotation, said six torque-transmitting mechanisms beingengaged in combinations of three to establish at least seven forwardspeed ratios and one reverse speed ratio between said input shaft andsaid output shaft.
 6. The transmission defined in claim 5, wherein afirst of said six torque-transmitting mechanisms is operable, forselectively interconnecting a member of said first or third planetarygear set with said input shaft.
 7. The transmission defined in claim 5,wherein a second of said six torque-transmitting mechanisms is operablefor selectively interconnecting a member of said second or thirdplanetary gear set with said input shaft.
 8. The transmission defined inclaim 5, wherein a third of said six torque-transmitting mechanisms isoperable for selectively interconnecting a member of said first orsecond planetary gear set with said input shaft or with a member of saidthird planetary gear set.
 9. The of transmission defined in claim 5,wherein a fourth of said six torque-transmitting mechanisms is operablefor selectively interconnecting a member of said first planetary gearset with a member of said second or third planetary gear set.
 10. Thetransmission defined in claim 5, wherein a fifth of said sixtorque-transmitting mechanisms is operable for selectivelyinterconnecting a member of said third planetary gear set with a memberof said first or second planetary gear set.
 11. The transmission definedin claim 5, wherein a sixth of said six torque-transmitting mechanismsis operable for selectively interconnecting a member of said first,second or third planetary gear set with another member of said first,second or third planetary gear set, the pair of members interconnectedby said sixth torque-transmitting mechanism being different from themembers interconnected with said input shaft by a first, second andthird of said six torque-transmitting mechanisms, respectively, and fromthe pair of members interconnected by said third, a fourth and a fifthof said six torque-transmitting mechanisms, respectively.
 12. Thetransmission defined in claim 5, wherein each of said planetary gearsets includes a planet carrier assembly member, and wherein said planetcarrier assembly member of each of said planetary gear sets is asingle-pinion carrier.
 13. The family of transmission in claim 5,wherein each of said planetary gear sets includes a planet carrierassembly member, and wherein at least one planet carrier assembly memberof one of said planetary gear sets is a double-pinion carrier.